| name | screenstudio-alt |
| description | Open-source headless Screen Studio alternative: auto speed-up of idle, auto-zoom on click clusters, keystroke overlay chips, smoothed synthetic cursor, and 9:16 vertical export that follows the action — post-production for screen recordings from the CLI. |
| risk | safe |
| source | community |
| source_type | community |
| source_repo | connerkward/screenstudio-alternative-skill |
| date_added | 2026-06-16 |
| author | Conner K Ward |
| license | MIT |
| tags | ["screen-recording","video","post-production","auto-zoom","vertical-video","ffmpeg"] |
| tools | ["claude-code","antigravity","cursor","gemini-cli","codex-cli"] |
When to Use
Use when polishing a screen recording / demo video for sharing, when the user mentions Screen Studio, auto-zoom, idle speed-up, or vertical/social video from a screen capture, and for any social-facing demo (vertical output is the default for those).
Source: connerkward/screenstudio-alternative-skill (MIT).
screenstudio-alt
The skill's code lives in this directory (polish.py, render.py, studio.py,
events-log.swift, test fixtures, etc.). Published publicly as
connerkward/screen-studio-alternative via the publish-skill skill.
Two components:
events-log (Swift) — capture-side input logger (cursor 60Hz, clicks, keys;
drops keys during macOS secure input). Runs ONLY while recording. Needs
Accessibility/Input Monitoring for the terminal. Auto-zoom/keys/cursor need
this data at capture time — it cannot be recovered from pixels later.
polish.py (Python, ffmpeg + PIL) — the post-production pass:
python3 src/polish.py in.mp4 --events in.events.jsonl \
--speedup
--zoom
--keys
--smooth-cursor
--vertical
--speedup works WITHOUT events (freezedetect only) — usable on the whole
existing dailies corpus.
render.py — high-quality non-destructive renderer (preferred): single-pass
spring-physics camera over the original high-res frames, LANCZOS into a smaller
target (crisp zoom, ~1.3× sharper than the ffmpeg upscale path), 60fps, H + 9:16 V.
Tunable --freq/--zeta (spring), --fps, --target-w. Takes explicit
--regions [{t0,t1,z,cx,cy}]. polish.py is the older ffmpeg-filter fallback.
studio.py [recording.mp4] — local web UI, NLE-style fixed-ruler timeline (bar =
source duration, never rescales → upstream always planted): zoom regions are draggable
blocks (move / retime edges / click to add / double-click delete); idle spans are
speed blocks with rate-only editing — source range locked, rate set via inspector
slider on select or right-edge rate-stretch drag (FCP retime / Premiere Rate
Stretch); rate changes ripple downstream only. Tunable cosine-ease ramp, default zoom,
aspect, frame styling. Always-smooth synthetic cursor + click ripple + real recorded
click sound (CC0 #735771). Export uses render.py. Free port, local. (Keystroke overlay
exists in the engine but is off by default.)
Easy path
screencast.sh --demo (screencast skill) does the whole chain: starts the event
logger, records, then polishes + emits the 9:16 vertical automatically. Vertical
is the DEFAULT for social-facing demos.
Gotchas (learned the hard way, kept here so they're not relearned)
- ffmpeg CANNOT do animated
scale=eval=frame → crop (link reinit wedges crop's
per-frame exprs). That's why zoom uses zoompan (no t var there — use on/FPS).
- This machine's ffmpeg lacks
drawtext; all text/cursor overlays are PIL-rendered
PNGs + overlay.
- Test rig:
make-fixture.py synthesizes a fake screen recording + ground-truth
events.jsonl — validate any change against it before trusting real footage.
Limitations
- The workflow assumes FFmpeg plus the companion scripts are available locally; it is not a hosted video editor.
- Polished cursor, click, and keystroke effects depend on event logs captured during recording; missing logs limit what can be reconstructed.
- Auto-zoom and idle speed-up still need human review for pacing, framing, and platform-specific taste.